Determination of Copper in Hydroponic Nutrient Solutions by UV-Visible Spectrophotometry and Flow Injection Analysis

Abstract

Copper (Cu) is a micronutrient that plays an important role in the growth of plants. A spectrophotometric analysis method has been developed to determine Cu2+ in hydroponic nutrient solutions. 4-(2-pyridylazo)-resorcinol (PAR), 1-(2 pyridylazo)-2-naphthol (PAN) and 1-(2-thiazolylazo)-2-naphthol (TAN) ligands were studied as co-complexants that will enable determination of Cu2+. Each microelement has an optimum pH value at which it forms a complex with the ligand. By studying the effect of pH on the metal-ligand complex, the optimum pH values at which maximum absorbances were obtained were determined. The interference effects of foreign ions in the nutrient solution were examined. 4-(2-pyridylazo)-resorcinol (PAR) complexes were found to be more resistant to foreign ion interference. For this reason, validation studies of the method developed for 4-(2-pyridylazo)-resorcinol (PAR) complexes were carried out. Afterwards, the developed method was adapted to the flow injection analysis system. The procedure is simple, rapid and reliable. This method was successfully applied to the determination of copper in hydroponic nutrient solutions.

Keywords

• Micronutrients
• hydroponic nutrient solution
• spectrophotometry
• flow injection analysis

References

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